1. Field of the Invention
The present invention relates to a shift register circuit, and more particularly, to a shift register circuit applied to LTPS (low temperature poly silicon) LCDs.
2. Description of the Related Art
Characteristics of high definition, multicolor display, low power consumption, lower voltage requirements and light weight make liquid crystal displays (LCDs) a leading display device technology. LCDs have been used for several years as mobile information displays in, for example, personal digital assistants (PDAs), portable computers, mobile phones, and the like.
Recently, CMOS shift register circuits are widely applied to LTPS liquid crystal display (LCD). However, at least eight masks are required to form the CMOS shift register circuit during the fabrication, and thus, the costs are raised.
For cost reduction consideration, PMOS shift registers, which require much less masks, were used recently by LCD makers. However, conventional PMOS shift registers use dynamic circuit operation, which does not have a latch circuit. Thus, the operation voltage range is very high, even high up to 2 |VDD-VSS|.